GASP
The Genetic algorithm for structure prediction – GASP – predicts the structure and composition of stable and metastable phases of crystals, molecules, atomic clusters and defects from first-principles. The GASP program is interfaced to many energy codes including: VASP, LAMMPS, MOPAC, Gulp, JDFTx and can efficiently run on parallel architectures. For more information about the code and how to download, install and use it, see the GASP website: http://gasp.mse.cornell.edu.
Developers: William W. Tipton and Stewart Wenner
Publications
- Pressure-induced structure transitions in Eu metal to 92 GPa.
W. Bi, Y. Meng, R. S. Kumar, A. L. Cornelius, W. W. Tipton, R. G. Hennig, Y. Zhang, C. Chen, and J. S. Schilling.
Phys. Rev. B 83, 104106 (2011). [web] - Emergent reduction of electronic state dimensionality in dense ordered Li-Be alloys.
J. Feng, R. G. Hennig, N. W. Ashcroft and Roald Hoffmann.
Nature 451, 445 (2008). [web]
NXM
For the construction of atomic models of nano crystals based on their surface energies, we developed the Nanocrystal Maker - NXM. The program uses common crystal structure files as input and the surface energy of the relevant facets to construct structural models of nano crystals from visualization and further computational simulations.
Developer: William Dirschka
Manual and download: Coming soon.
Solvation Model
To describe heterogeneous solid/liquid materials interfaces we developed and implemented a new implicit solvation method for quantum Monte Carlo. The method requires neither thermodynamic sampling nor explicit solvent electrons. The method is based on a rigorous statistical treatment of the solvent and utilizes a variation theorem. Using a single empirical parameter we find the method accurately describes the solvation energies of various molecules such as formaldehyde illustrated on the right. The method is applicable to a range of challenges in materials science ranging from identifying transition states of molecules to surface reactions in liquid environments.
Developer: Katie Schwarz
We also implemented this solvation model into the widely used VASP code for efficient density-functional calculations of solvated materials.
Developers: Kiran Matthew